Background
Mastering motor milestones and social personal skills may lead to a developmental transition that initiates a cascade of developmental changes, including social interaction and language learning(1). For example, the onset of walking(1,2) and sitting skills(3) but also social-personal skills can predict children's vocabulary size, which may potentially affect literacy-related abilities in later life. Similarly, early abilities to distinguish prosody and rhythm may affect children’s progress in learning language and (social) communication. For example, musical rhythmicity is strongly linked to cognition due to the synchronization of the partner's language expression in social communication(4).
Various studies have shown the genetic overlap between interpersonal milestone development and neurodevelopmental disorders. For example, individuals diagnosed with Autism Spectrum Disorder (ASD) show delayed development of cognitive and social functioning and, therefore, may reach early developmental milestones later (smiling, walking, spoon feeding themselves, crawling) or not at all(5).

This project will use data from ALSPAC and other large cohorts to investigate the genetic architecture of early social/communicative/language abilities as well as social /social communication abilities during the life course within large consortia (e.g. meta-Genome Wide Association Analyses (GWAS) within the EAGLE consortium) including in-depth structural models of genetic factors. The study will biologically annotate the genetic architecture of early social/communicative abilities as well as social abilities through genetic enrichment and variance partitioning analyses. Once social behaviour has been modelled genetically, we will derive genetic tools to identify genetic overlap with neuro-developmental disorders and other health-related, educational and (social) behavioural outcomes in later life, as well as brain-related encodings (e.g. brain structure and function). The project will finally assess evidence for correlation and causal mechanisms linking precursors of social/communicative abilities (e.g. musicality, motor behaviour and temperament) to social performance and, in turn, social behaviour and social communication skills to later-life outcomes (e.g. health, education, behaviour).

1. Walle, E. A. Infant Social Development across the Transition from Crawling to Walking. Front. Psychol. 7, (2016).
2. Walle, E. A. & Campos, J. J. Infant language development is related to the acquisition of walking. Dev. Psychol. 50, 336–348 (2014).
3. Libertus, K. & Violi, D. A. Sit to Talk: Relation between Motor Skills and Language Development in Infancy. Front. Psychol. 7, (2016).
4. Ravignani, A., Honing, H. & Kotz, S. A. Editorial: The Evolution of Rhythm Cognition: Timing in Music and Speech. Front. Hum. Neurosci. 11, 303 (2017).
5. Kuo, S. S. et al. Developmental Variability in Autism Across 17 000 Autistic Individuals and 4000 Siblings Without an Autism Diagnosis: Comparisons by Cohort, Intellectual Disability, Genetic Etiology, and Age at Diagnosis. JAMA Pediatr. 176, 915–923 (2022).